Add support to skip install when CI=true

Context: Setting up Husky in CI is usually pointless, git usually used as read-only, not making commits in CI. But having .git/hooks initialized with husky can cause trouble if the next CI job is without node_modules and CI Runner has not provided clean .git.

Disabling husky install can be done with testing for $CI value:

"scripts": {
- "prepare": "husky install"
+ "prepare": "test -n \"$CI\" || husky install"
}

However, that is not portable (no POSIX shell on windows), so perhaps add --skip-ci option to husky install command:

"scripts": {
- "prepare": "husky install"
+ "prepare": "husky install --skip-ci"
}

[glensc]

at the time “prepare” script is present, husky and node_modules are there

If node_modules is there, install is-ci no?

Indeed it is! thanks.

[mondeja]

at the time “prepare” script is present, husky and node_modules are there

If node_modules is there, install is-ci no?